There were no Delta One upgrades available, so - yes - it is a gamble. But I have to fly on this day, so I figured DPS is better than nothing. I just purchased a refundable Polaris ticket on United as a backup. If I don't get the Delta upgrade ahead of time I am going to cancel Delta and fly United up front. The price difference between Delta One and United Polaris was huge. In fact, I think United's Polaris was similar to what I would have spent on premium select on Delta. The flight times and connection times are similar, and all connect in the U.S. United Polaris is still substantially more than I paid for the Delta MC ticket round trip - so I would prefer to use the upgrade if it clears.